Create flag for new App Pairs feature

This patch creates a new Launcher flag for the upcoming App Pairs feature.

Flag: ENABLE_APP_PAIRS
Bug: 274189428
Test: Not needed
Change-Id: I84cfb3742a60bd5633d71bc68e7506ac0c67e55f
diff --git a/src/com/android/launcher3/config/FeatureFlags.java b/src/com/android/launcher3/config/FeatureFlags.java
index b4fe748..2972489 100644
--- a/src/com/android/launcher3/config/FeatureFlags.java
+++ b/src/com/android/launcher3/config/FeatureFlags.java
@@ -404,6 +404,11 @@
             "ENABLE_APP_CLONING_CHANGES_IN_LAUNCHER", false,
             "Removes clone apps from the work profile tab.");
 
+    public static final BooleanFlag ENABLE_APP_PAIRS = getDebugFlag(274189428,
+            "ENABLE_APP_PAIRS", false,
+            "Enables the ability to create and save app pairs on the Home screen for easy"
+                    + " split screen launching.");
+
     public static class BooleanFlag {
 
         private final boolean mCurrentValue;